1. Field of the Invention
The present invention generally relates to a method for using exact stability integration in network designs. More particularly, the invention relates to a method for using exact stability in net-work designs for application in systems optimizing flight control of aircraft through the use of improved numerical techniques.
2. Description of the Prior Art
The idea of exact stability integration originated during the course of an U.S. Air Force study whose objective was to advance the flight control of aircraft through improved numerical techniques. One of the techniques that was investigated was a predictor-corrector approach that had exact stability for second and fourth order systems.
Mathematical literature describes integration algorithm in terms of order, i.e. first order, second order, - - - up to any order of which the computer is capable. However, integration at higher orders designs a system that is always stable and completely controllable with a deadbeat response. According to Warwick and Tham, the dead-beat response provides the required robustness of the system by causing the response of the estimation error to reach equilibrium in minimum time. Warwick, Kevin and Tham, Ming T., "Failsafe Control Systems," Chapman and Hall, New York, 1991, p. 126,127.
The intrinsic robustness of a dead-beat response is achieveable with an exact stability system (as opposed to an absolute stability system) inasmuch as the observer is strongly decoupled from unwanted disturbances and moderately decoupled from faults resulting in a network with a dead-beat response having the desired stability, robustness and controllability response desired which can be easily obtained when exact stability is used as a design tool and using the technique of process control. According to Kalman, exact stability provides complete control if there exists a sampled-data controller which has a dead-beat response. Kalman, R. E., "On the General Theory of Control Systems", First International Federation Automatic Control, Moscow, Butterworths, Vol. 1, pp 481-492 (1961).
Representative of the prior patent art directed to proportional integration system in combination with a dead-beat system is U.S. Pat. No. 4,979,940 (Bobo, Jr. et al.). The patent discloses an infusion system, methodology, and algorithm for identifying patient-induced pressure artifacts.
Representative of the prior patent art directed to network with order integration and controlling algorithm are U.S. Pat. No. 5,148,514 (Arima et al.), U.S. Pat. No. 5,224,203 (Skeirik), U.S. Pat. No. 5,282,261 (Skeirik), and U.S. Pat. No. 5,293,457 (Arima et al.). Arima et al. discloses neural network integrated circuit device having self-organizing function. Skeirik discloses on-line process control neural network using data pointers, and neural network process measurement and control.
Representative of the prior patent art directed to high order information processing for a network that has a controlling algorithm and order integration is U.S. Pat. No. 5,513,923 (Matsuba et al.). The patent discloses high order information processing method by means of a neural network and minimum and maximum searching method therefor.
Representative of the prior patent art of general interest are U.S. Pat. No. 5,197,114 (Skeirik) directed to computer neural network regulatory process control system and method; U.S. Pat. No. 5,629,845 (Liniger) directed to parallel computation of the response of a physical system; and U.S. Pat. No. 5,634,004 (Gopinath et al.) directed to directly programmable distribution element.
While many of the neural network systems with order integration and controlling algorithm disclosed in the prior art generally have achieved the objectives for which they were designed, none disclose a neural network system which embodies an algorithm with integration orders as high as desired for optimization problems. Consequently, the need still exists for a neural network system exact stability algorithm, with the value of integration orders restricted by computer memory capacity, that always has dead-beat control with minimal extraneous errors added to the system.